Bioactive secondary metabolites from endophytic strains of collected from desert plants.

Endophytic fungi from desert plants belong to a unique microbial community that has been scarcely investigated chemically and could be a new resource for bioactive natural products. In this study, 13 secondary metabolites () with diverse carbon skeletons, including a novel polyketide (1) with a unique 5,6-dihydro-4,7-2,6-methanopyrano[4,3-][1,3]dioxocin-7-one ring system and three undescribed polyketides (, , and ), were obtained from the endophytic fungus isolated from two desert plant species. Different approaches, including HR-ESI-MS, UV spectroscopy, IR spectroscopy, NMR, and CD, were used to determine the planar and absolute configurations of the compounds.

Undescribed diphenyl ethers betaethrins A-I from a desert plant endophytic strain of the fungus Phoma betae A.B. Frank (Didymellaceae).

Ten diphenyl ethers (DPEs), including nine undescribed analogs named betaethrins A-I, were isolated from the desert plant endophytic fungus Phoma betae A.B. Frank (Didymellaceae).

Phaeosphspirone (1/1'), a pair of unique polyketide enantiomers with an unusual 6/5/5/6 tetracyclic ring from the desert plant endophytic fungus Phaeosphaeriaceae sp.

Phaeosphspirone, an undescribed polyketide with a unique 6/5/5/6-fused tetracyclic system, and two known analogues, herbarin and O-methylherbarin, were purified from the endophytic fungus Phaeosphaeriaceae sp. isolated from the desert plant Bassia dasyphylla. The connectivity and relative configuration of phaeosphspirone was elucidated by comprehensive HR-ESI-MS and NMR analysis together with a computer-assisted structure elucidation (CASE) method.

UPLC-Q-TOF-MS/MS analysis of the guaiane sesquiterpenoids oxytropiols A-J and detection of undescribed analogues from the locoweed endophytic fungus Alternaria oxytropis (Pleosporaceae).

Introduction: In addition to the mycotoxin swainsonine, the locoweed endophytic fungus Alternaria oxytropis (Pleosporaceae) also produces a series of rarely reported, highly oxygenated bicyclic guaiane sesquiterpenoids. Few investigations on the electrospray tandem mass fragmentation pattern of this sesquiterpenoid have been reported.

Objectives: We aimed to analyze and detect new guaiane sesquiterpenoid analogues from crude extracts of the locoweed endophytic fungus A.

Bioactive metabolites from the desert plant-associated endophytic fungus Chaetomium globosum (Chaetomiaceae).

Globosumin, an undescribed chromene-4,7(4aH)-dione-tetramic acid PKS-PKS-NRPS hybrid, and globosumone, an undescribed azaphilone, together with ten known metabolites, were isolated from the desert plant-associated endophytic fungus Chaetomium globosum (Chaetomiaceae). The planar structures and relative configurations of globosumin and globosumone were determined by high-resolution ESI-MS and NMR data, and the absolute configurations of these two metabolites were determined by electronic circular dichroism (ECD) and circular dichroism (CD) combined with time-dependent density functional theory (TDDFT)-based quantum-chemical calculations. Chaetoglobosin A displayed biological effects against the seedling growth of Arabidopsis thaliana (Brassicaceae) in a dose-dependent manner, and this compound also exhibited biological activity against two cancer cell lines, A549 and HepG2, with IC values of 6.

New species in section and an overview of section .

sections and are accommodated in the subgenus . In the present study, a polyphasic approach using morphology and multi-gene phylogeny was applied to investigate the taxonomy of these two sections. Based on the phylogenetic analysis, section includes 25 species, which can be assigned to four series: , , and is newly described in this section and this species was isolated from a cigarette from PR China and belongs to series .

New section and species in .

is a monophyletic genus containing seven sections. The number of species in grows rapidly due to reliable and complete sequence data contributed from all over the world. In this study agricultural soil samples from Fujiang, Guangdong, Jiangxi, Shandong, Tibet and Zhejiang provinces of China were collected and analyzed for fungal diversity.

Bioactive -Sativene Sesquiterpenoids from an Endophytic Fungus, .

A series of -sativene sesquiterpenoids (-) including two new natural products ( and ), four new analogues (-), and six known analogues, helminthosporic acid (), drechslerine A (), drechslerine B (), helminthosporol (), helminthosporal acid (), and isosativenediol (), were purified from the endophytic fungus isolated from a desert plant, . The stereochemistry of helminthosporic acid () was established for the first time by X-ray diffraction, and the structures including relative and absolute configurations of these new compounds were determined by NMR and CD spectra together with biosynthetic considerations. Compounds - are the first -sativene sesquiterpenoids possessing a glucose group on C-15, C-15, and C-14, respectively.

Chetocochliodins A-I, Epipoly(thiodioxopiperazines) from .

Nine new epipoly(thiodioxopiperazine) (ETP) analogues, chetocochliodins AI (-), along with two known ones, chetoseminudins E and C ( and ), were purified from the fungus . The planar structures and absolute configurations of these new compounds were determined by extensive NMR spectroscopic analysis, CD spectra, and chemical reactions. Shielding effects from the indole on the 3-SCH/3-OCH/3-OCH- groups facilitated the determination of relative configuration of the analogues.

Bioactive Resorcylic Acid Lactones with Different Ring Systems from Desert Plant Chaetosphaeronema hispidulum. [corrected].

Five new resorcylic acid lactones (RALs) hispidulactones A-E (1, 4, 5, 8, and 9), a new natural product (2), and four known ones (3, 6, 7, and 10) with different ring systems were isolated from the desert plant Chaetosphaeronema hispidulum. [corrected]. The new compounds were characterized by NMR data, CD spectra, and X-ray experiment.

Spiciferone analogs from an endophytic fungus Phoma betae collected from desert plants in West China.

Endophytic fungi from desert, arid, and grassland areas are an ecologically important but unique group with poor chemical investigation. During our ongoing study to mine bioactive secondary metabolites from unique fungal environments, a new shunt product spiciferone F (1) including two new analogs spiciferones G (2) and H (3) together with four known ones spiciferone A (4), spiciferol A (5), 6, and 7 were isolated from endophytic fungus Phoma betae inhabiting in plant Kalidium foliatum (Pall.) Moq from Ningxia Province of West China.

Hematological Risk Factors for High-Altitude Headache in Chinese Men Following Acute Exposure at 3,700 m.

High-altitude headache (HAH) is a notably common disorder affecting the daily life of travelers ascending to high altitude. Hematological parameters are important clinical examinations for various diseases. Today, hematological characteristics of HAH remain unrevealed.

Elevated pentose phosphate pathway is involved in the recovery of hypoxia‑induced erythrocytosis.

As a typical model of hypoxia‑induced excessive erythrocytosis, high altitude polycythemia (HAPC) results in microcirculation disturbance, aggravates tissue hypoxia and results in a severe clinical outcome, without any effective intervention methods except for returning to an oxygen‑rich environment. The present study aimed to explore potential therapeutic targets which may participate in the recovery of HAPC by studying the mechanisms of reducing the hemoglobin (HB) concentration during re‑oxygenation. A total of 14 and 13 subjects were recruited over a 5,300 m distance and 5,170 m area.

UPLC‑QTOFMS‑based metabolomic analysis of the serum of hypoxic preconditioning mice.

Hypoxic preconditioning (HPC) is well‑known to exert a protective effect against hypoxic injury; however, the underlying molecular mechanism remains unclear. The present study utilized a serum metabolomics approach to detect the alterations associated with HPC. In the present study, an animal model of HPC was established by exposing adult BALB/c mice to acute repetitive hypoxia four times.

Activated corticosterone synthetic pathway is involved in poor responses to re-oxygenation after prolonged hypoxia.

Diverse response patterns to re-oxygenation lead to various physiological or pathological phenotypes, but now lack of systematic research models in vivo. High-altitude de-acclimatization syndrome (HADAS) describes systematic alterations of re-oxygenation returning to plain after a long living in high altitude. In this study, we aim at employing a comprehensive metabolomics to explore the mechanisms for different reactions to re-oxygenation based on systematic quantitation scoring methods of HADAS model.

A Signature of Circulating microRNAs Predicts the Susceptibility of Acute Mountain Sickness.

Acute mountain sickness (AMS) is a common disabling condition in individuals experiencing high altitudes, which may progress to life-threatening high altitude cerebral edema. Today, no established biomarkers are available for prediction the susceptibility of AMS. MicroRNAs emerge as promising sensitive and specific biomarkers for a variety of diseases.

Physiological Adjustments and Circulating MicroRNA Reprogramming Are Involved in Early Acclimatization to High Altitude in Chinese Han Males.

Altitude acclimatization is a physiological process that restores oxygen delivery to the tissues and promotes oxygen use under high altitude hypoxia. High altitude sickness occurs in individuals without acclimatization. Unraveling the molecular underpinnings of altitude acclimatization could help understand the beneficial body responses to high altitude hypoxia as well as the altered biological events in un-acclimatized individuals.

Metabolite Modulation in Human Plasma in the Early Phase of Acclimatization to Hypobaric Hypoxia.

The exposure of healthy subjects to high altitude represents a model to explore the pathophysiology of diseases related to tissue hypoxia. We explored a plasma metabolomics approach to detect alterations induced by the exposure of subjects to high altitude. Plasma samples were collected from 60 subjects both on plain and at high altitude (5300 m).

Identification of ochratoxin A producing fungi associated with fresh and dry liquorice.

The presence of fungi on liquorice could contaminate the crop and result in elevated levels of mycotoxin. In this study, the mycobiota associated with fresh and dry liquorice was investigated in 3 producing regions of China. Potential toxigenic fungi were tested for ochratoxin A (OTA) and aflatoxin B1 (AFB1) production using liquid chromatography/mass spectrometry/mass spectrometry.